/*
   *	Comtrol SV11 card driver
   *
   *	This is a slightly odd Z85230 synchronous driver. All you need to
   *	know basically is
   *
   *	Its a genuine Z85230
   *
   *	It supports DMA using two DMA channels in SYNC mode. The driver doesn't
   *	use these facilities
   *	
   *	The control port is at io+1, the data at io+3 and turning off the DMA
   *	is done by writing 0 to io+4
   *
   *	The hardware does the bus handling to avoid the need for delays between
   *	touching control registers.
   *
   *	Port B isn't wired (why - beats me)
   *
   *	Generic HDLC port Copyright (C) 2008 Krzysztof Halasa <khc@pm.waw.pl>
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/mm.h>
  #include <linux/net.h>
  #include <linux/skbuff.h>
  #include <linux/netdevice.h>
  #include <linux/if_arp.h>
  #include <linux/delay.h>
  #include <linux/hdlc.h>
  #include <linux/ioport.h>
  #include <linux/slab.h>
  #include <net/arp.h>
  
  #include <asm/irq.h>
  #include <asm/io.h>
  #include <asm/dma.h>
  #include <asm/byteorder.h>
  #include "z85230.h"
  
  static int dma;
  
  /*
   *	Network driver support routines
   */
  
  static inline struct z8530_dev* dev_to_sv(struct net_device *dev)
  {
  	return (struct z8530_dev *)dev_to_hdlc(dev)->priv;
  }
  
  /*
   *	Frame receive. Simple for our card as we do HDLC and there
   *	is no funny garbage involved
   */
  
  static void hostess_input(struct z8530_channel *c, struct sk_buff *skb)
  {
  	/* Drop the CRC - it's not a good idea to try and negotiate it ;) */
  	skb_trim(skb, skb->len - 2);
  	skb->protocol = hdlc_type_trans(skb, c->netdevice);
  	skb_reset_mac_header(skb);
  	skb->dev = c->netdevice;
  	/*
  	 *	Send it to the PPP layer. We don't have time to process
  	 *	it right now.
  	 */
  	netif_rx(skb);
  }
  
  /*
   *	We've been placed in the UP state
   */
  
  static int hostess_open(struct net_device *d)
  {
  	struct z8530_dev *sv11 = dev_to_sv(d);
  	int err = -1;
  
  	/*
  	 *	Link layer up
  	 */
  	switch (dma) {
  		case 0:
  			err = z8530_sync_open(d, &sv11->chanA);
  			break;
  		case 1:
  			err = z8530_sync_dma_open(d, &sv11->chanA);
  			break;
  		case 2:
  			err = z8530_sync_txdma_open(d, &sv11->chanA);
  			break;
  	}
  
  	if (err)
  		return err;
  
  	err = hdlc_open(d);
  	if (err) {
  		switch (dma) {
  			case 0:
  				z8530_sync_close(d, &sv11->chanA);
  				break;
  			case 1:
  				z8530_sync_dma_close(d, &sv11->chanA);
  				break;
  			case 2:
  				z8530_sync_txdma_close(d, &sv11->chanA);
  				break;
  		}
  		return err;
  	}
  	sv11->chanA.rx_function = hostess_input;
  
  	/*
  	 *	Go go go
  	 */
  
  	netif_start_queue(d);
  	return 0;
  }
  
  static int hostess_close(struct net_device *d)
  {
  	struct z8530_dev *sv11 = dev_to_sv(d);
  	/*
  	 *	Discard new frames
  	 */
  	sv11->chanA.rx_function = z8530_null_rx;
  
  	hdlc_close(d);
  	netif_stop_queue(d);
  
  	switch (dma) {
  		case 0:
  			z8530_sync_close(d, &sv11->chanA);
  			break;
  		case 1:
  			z8530_sync_dma_close(d, &sv11->chanA);
  			break;
  		case 2:
  			z8530_sync_txdma_close(d, &sv11->chanA);
  			break;
  	}
  	return 0;
  }
  
  static int hostess_ioctl(struct net_device *d, struct ifreq *ifr, int cmd)
  {
  	/* struct z8530_dev *sv11=dev_to_sv(d);
  	   z8530_ioctl(d,&sv11->chanA,ifr,cmd) */
  	return hdlc_ioctl(d, ifr, cmd);
  }
  
  /*
   *	Passed network frames, fire them downwind.
   */
  
  static netdev_tx_t hostess_queue_xmit(struct sk_buff *skb,
  					    struct net_device *d)
  {
  	return z8530_queue_xmit(&dev_to_sv(d)->chanA, skb);
  }
  
  static int hostess_attach(struct net_device *dev, unsigned short encoding,
  			  unsigned short parity)
  {
  	if (encoding == ENCODING_NRZ && parity == PARITY_CRC16_PR1_CCITT)
  		return 0;
  	return -EINVAL;
  }
  
  /*
   *	Description block for a Comtrol Hostess SV11 card
   */
  
  static const struct net_device_ops hostess_ops = {
  	.ndo_open       = hostess_open,
  	.ndo_stop       = hostess_close,
  	.ndo_change_mtu = hdlc_change_mtu,
  	.ndo_start_xmit = hdlc_start_xmit,
  	.ndo_do_ioctl   = hostess_ioctl,
  };
  
  static struct z8530_dev *sv11_init(int iobase, int irq)
  {
  	struct z8530_dev *sv;
  	struct net_device *netdev;
  	/*
  	 *	Get the needed I/O space
  	 */
  
  	if (!request_region(iobase, 8, "Comtrol SV11")) {
  		pr_warn("I/O 0x%X already in use
  ", iobase);
  		return NULL;
  	}
  
  	sv = kzalloc(sizeof(struct z8530_dev), GFP_KERNEL);
  	if (!sv)
  		goto err_kzalloc;
  
  	/*
  	 *	Stuff in the I/O addressing
  	 */
  
  	sv->active = 0;
  
  	sv->chanA.ctrlio = iobase + 1;
  	sv->chanA.dataio = iobase + 3;
  	sv->chanB.ctrlio = -1;
  	sv->chanB.dataio = -1;
  	sv->chanA.irqs = &z8530_nop;
  	sv->chanB.irqs = &z8530_nop;
  
  	outb(0, iobase + 4);		/* DMA off */
  
  	/* We want a fast IRQ for this device. Actually we'd like an even faster
  	   IRQ ;) - This is one driver RtLinux is made for */
  
  	if (request_irq(irq, z8530_interrupt, 0,
  			"Hostess SV11", sv) < 0) {
  		pr_warn("IRQ %d already in use
  ", irq);
  		goto err_irq;
  	}
  
  	sv->irq = irq;
  	sv->chanA.private = sv;
  	sv->chanA.dev = sv;
  	sv->chanB.dev = sv;
  
  	if (dma) {
  		/*
  		 *	You can have DMA off or 1 and 3 thats the lot
  		 *	on the Comtrol.
  		 */
  		sv->chanA.txdma = 3;
  		sv->chanA.rxdma = 1;
  		outb(0x03 | 0x08, iobase + 4);		/* DMA on */
  		if (request_dma(sv->chanA.txdma, "Hostess SV/11 (TX)"))
  			goto err_txdma;
  
  		if (dma == 1)
  			if (request_dma(sv->chanA.rxdma, "Hostess SV/11 (RX)"))
  				goto err_rxdma;
  	}
  
  	/* Kill our private IRQ line the hostess can end up chattering
  	   until the configuration is set */
  	disable_irq(irq);
  
  	/*
  	 *	Begin normal initialise
  	 */
  
  	if (z8530_init(sv)) {
  		pr_err("Z8530 series device not found
  ");
  		enable_irq(irq);
  		goto free_dma;
  	}
  	z8530_channel_load(&sv->chanB, z8530_dead_port);
  	if (sv->type == Z85C30)
  		z8530_channel_load(&sv->chanA, z8530_hdlc_kilostream);
  	else
  		z8530_channel_load(&sv->chanA, z8530_hdlc_kilostream_85230);
  
  	enable_irq(irq);
  
  	/*
  	 *	Now we can take the IRQ
  	 */
  
  	sv->chanA.netdevice = netdev = alloc_hdlcdev(sv);
  	if (!netdev)
  		goto free_dma;
  
  	dev_to_hdlc(netdev)->attach = hostess_attach;
  	dev_to_hdlc(netdev)->xmit = hostess_queue_xmit;
  	netdev->netdev_ops = &hostess_ops;
  	netdev->base_addr = iobase;
  	netdev->irq = irq;
  
  	if (register_hdlc_device(netdev)) {
  		pr_err("unable to register HDLC device
  ");
  		free_netdev(netdev);
  		goto free_dma;
  	}
  
  	z8530_describe(sv, "I/O", iobase);
  	sv->active = 1;
  	return sv;
  
  free_dma:
  	if (dma == 1)
  		free_dma(sv->chanA.rxdma);
  err_rxdma:
  	if (dma)
  		free_dma(sv->chanA.txdma);
  err_txdma:
  	free_irq(irq, sv);
  err_irq:
  	kfree(sv);
  err_kzalloc:
  	release_region(iobase, 8);
  	return NULL;
  }
  
  static void sv11_shutdown(struct z8530_dev *dev)
  {
  	unregister_hdlc_device(dev->chanA.netdevice);
  	z8530_shutdown(dev);
  	free_irq(dev->irq, dev);
  	if (dma) {
  		if (dma == 1)
  			free_dma(dev->chanA.rxdma);
  		free_dma(dev->chanA.txdma);
  	}
  	release_region(dev->chanA.ctrlio - 1, 8);
  	free_netdev(dev->chanA.netdevice);
  	kfree(dev);
  }
  
  static int io = 0x200;
  static int irq = 9;
  
  module_param(io, int, 0);
  MODULE_PARM_DESC(io, "The I/O base of the Comtrol Hostess SV11 card");
  module_param(dma, int, 0);
  MODULE_PARM_DESC(dma, "Set this to 1 to use DMA1/DMA3 for TX/RX");
  module_param(irq, int, 0);
  MODULE_PARM_DESC(irq, "The interrupt line setting for the Comtrol Hostess SV11 card");
  
  MODULE_AUTHOR("Alan Cox");
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("Modular driver for the Comtrol Hostess SV11");
  
  static struct z8530_dev *sv11_unit;
  
  int init_module(void)
  {
  	if ((sv11_unit = sv11_init(io, irq)) == NULL)
  		return -ENODEV;
  	return 0;
  }
  
  void cleanup_module(void)
  {
  	if (sv11_unit)
  		sv11_shutdown(sv11_unit);
  }